---
id: "pos-of"
keywords: ["pos of"]
name: "__POS_OF__"
summary: "This is the `__POS_OF__` special value."
category: "specialvalues"
---

`__POS_OF__(expression)` returns a tuple consisting of `(position, expression)`, corresponding to the position of the expression you pass as a parameter here.
The `position` is a tuple consisting of `(fileName, lineNumber, columnNumberStart, columnNumberEnd)`.

It basically provides the same information as `__LOC_OF__`, but separated into multiple values.

**Note**: `expression` refers to any expression, it does not need to be a function.

<CodeTab labels={["ReScript", "JS Output"]}>

```res example
let f = () => None
let (pos, f') = __POS_OF__(f)

pos->Console.log
f'->Console.log
```

```js
function f(param) {}

var pos = ["testmodule.res", 2, 27, 28];

console.log(pos);
console.log(f);
var f$p = f;
```

</CodeTab>
